For simple (very simple) township maps I use:
http://www.skcensus.com/census/va/index.html
Frederick Co. Virginia's at:
http://www.skcensus.com/census/va/frederick.html
Twp. "Not Stated" may just be a term ancestry.com data-input-folks use to
fill in a required blank when the census was taken county-wide in the early
years. (By the1860 townships are pretty well designated throughout the
census enumeration for all States & Territories.)
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